The Bogo-Indian Defense for Black

1.d4 Nf6 2.c4 e6 3.Nf3 Bb4 4.Bd2 Qe7

The Bogo-Indian is the slim road against 3.Nf3: with 3...Bb4 Black gives check, and after 4.Bd2 the Nimzowitsch Variation 4...Qe7 protects the bishop. The queen keeps the square e5 in view and leaves you the choice of trading on d2. Against the main road 5.g3 the course plays 5...Nc6: the knight attacks d4 and prepares e5. After 6.Bg2 you trade with 6...Bxd2 and put your pawns on the dark squares with d6 and e5; after 6.Nc3 you take with 6...Bxc3 and jump with 7...Ne4 against the bishop on c3. Stockfish sees White slightly ahead in all lines, by two to four tenths – a normal value for Black in a solid opening. The course rests on 2744 games. White's other roads are 5.Nc3 and 5.e3.

After the bishop trade the pawns belong on the dark squares: d6 and e5 replace the missing bishop.
If White pushes past with d5, the knight on c6 retreats – via b8 to a6 and c5, or via d8 to f7.
With the centre closed, Black plays on the kingside with f5, White on the queenside with c5 and b4.
The pawn on a5 secures the square c5 for the knight and slows down b4.
When White opens with c5 and cxd6, always recapture with the c-pawn – the queen move to d6 costs material in several lines.